#include<stdio.h>
#include<assert.h>

const char* my_strstr(const char* str1,const char* str2)
{
	const char* s1=str1;
	const char* p=str1;
	const char* s2=str2;
	while(*p)
	{
		s1=p;
		s2=str2;
		while(*s1&&*s2&&*s1==*s2)
		{
			s1++;
			s2++;
		}
		if(*s2=='\0')
			return p;
		p++;
	}
	return NULL;
}

int main()
{
	char arr1[]="hellllo world";
	char arr2[]="llo";
	const char* pc=my_strstr(arr1,arr2);
	if(pc==NULL)
		printf("no!!!");
	else
		printf("%s",pc);
	return 0;
}
